A spark plug device similar to that described above is known, for example, from document DE 10 2014 015707 A1
This document discloses a prechamber spark plug that has a spark plug housing and a prechamber cap. The prechamber cap also includes a central transfer opening. The prechamber spark plug has a central electrode in the middle and a ground electrode device that at least partially encloses the central electrode in order to form a spark gap, the central electrode protrudes out from the ground electrode device.
Generally, prechamber spark plugs have a prechamber at the front end, with a spark gap positioned inside it. The prechamber is connected via openings to the actual combustion chamber. Such prechamber spark plugs can be used, for example, for igniting lean fuel mixtures, for example in gas-powered internal combustion engines. The prechamber in this case is a kind of pre-combustion chamber. Mixture flowing into the prechamber is ignited by means of an ignition spark. The flame that this produces in the prechamber is conveyed via the openings in the direction of the combustion chamber and ignites the lean mixture therein.
From document DE 10 2010 004851 B4, another prechamber spark plug is known in which cylindrical surfaces of a central electrode and a ground electrode undergo high-precision machining.
Document DE 10 2014 015707 A1 also discloses embodying the free end of the central electrode tip as concave. A fuel mixture flowing into the prechamber cap strikes the end of the central electrode tip and this generates turbulence. The generation of turbulence produces a flow in the front part of the prechamber, which contains a pronounced vertical directional component, which is directed toward the end of the prechamber cap and toward the central opening. In addition, lateral transfer openings are provided in the prechamber cap, through which mixture flows in, which causes a sharp pressure drop between a spark plug housing end of the spark gap and a prechamber end of the spark gap. This is intended to produce an improved “active” flushing of the electrode gap in the direction from the breathing space to the end of the prechamber 7.